JPH11230225A - Method for producing vibration control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a vibration control device which can eliminate press fitting-in structure of metal members, facilitate the manufacturing and reduce cost thereof. SOLUTION: The method comprises the steps of: forming an intermediate product composed of a shaft member 1, an outer member 2 made of an aluminum alloy and having a cylindrical portion 21 outwardly spaced from the shaft member 1 in a coaxial relationship therewith, and an elastic rubber body 3 joined to an outer surface of the shaft member 1 and an inner surface of the cylindrical portion 21 so as to connect the two 1, 21 integrally; and drawing the cylindrical portion 21 to reduce the diameter thereof for deforming the portion 21 plastically by forcing the cylindrical portion 21 into a first reduction hole 51 of a drawing machine which includes the first reduction hole 51 having a predetermined diameter at least smaller than the outer diameter of the cylindrical portion 21. Accordingly, the elastic rubber body 3 is compressed along the reduction of the diameter of the cylindrical portion 21 and is imparted with internal pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing an anti-vibration device suitably used, for example, as a suspension arm or an engine mount mounted on an automobile.

[0002]

2. Description of the Related Art Conventionally, for example, a suspension bush used as an anti-vibration connection device at a connection portion of a suspension arm of an automobile has been known. This bush
As shown in FIG. 7, a pipe-shaped inner cylinder fitting 101, an outer cylinder fitting 102 arranged substantially coaxially at a distance outside the inner cylinder fitting 101, an outer peripheral surface of the inner cylinder fitting 101, and an outer cylinder It comprises a substantially cylindrical rubber elastic body 103 which is vulcanized and adhered to the inner peripheral surface of the metal fitting 102 and integrally connects the two.

[0003] In consideration of the characteristics and durability of the rubber elastic body 103, this bush is made of an outer cylindrical metal fitting 10 as shown in FIG.
2 after drawing and compressing and deforming radially inward,
As shown in FIG. 9, the outer cylinder fitting 1 is attached to the inner peripheral surface of the mounting hole 141 provided at one end of the suspension arm 104.
02 is press-fitted and fixed. The mounting shaft portion such as the other connecting arm is fitted and fixed to the inner hole of the inner cylindrical fitting 101 by bolting or the like, and is provided for use.

[0004]

However, in the above-mentioned conventional bush, the outer cylinder 102 is provided with the suspension arm 1.
04 by press-fitting into the mounting hole 141 of
High accuracy is required for the outer diameter of the outer cylinder fitting 102. However, the outer cylinder fitting 10 which has been subjected to the drawing process before the press-fitting operation is performed.
Since it is difficult to obtain satisfactory dimensional accuracy of No. 2, if it is used as it is after drawing, it is difficult to secure sufficient and stable press-fitting workability and press-fit fixing strength.

That is, if the outer diameter of the outer cylindrical member 102 is too small over the entire circumference in the circumferential direction or partly smaller than the inner diameter of the mounting hole 141, squeezing or the like occurs at the time of press-fitting, making press-fitting extremely difficult. Becomes On the other hand, if the outer diameter of the outer cylindrical member 102 is too large over the entire circumference or partially with respect to the inner diameter of the mounting hole 141, it is difficult to secure sufficient press-fitting fixing strength.

In the prior art, however, a necessary dimensional accuracy has been ensured by subjecting the outer metal fitting 102 which has been subjected to the drawing processing to further polishing or the like. This requires a complicated process and equipment, which causes a problem in that the production is troublesome and the cost is greatly increased. The present invention has been devised in view of the above problems, and has been made to solve the problem of providing a method of manufacturing an anti-vibration device that can eliminate a press-fitting structure between metal members and can facilitate manufacturing and reduce costs. Should be an issue to be addressed.

[0007]

According to a first aspect of the present invention, there is provided an aluminum alloy having a shaft member and a cylindrical portion disposed substantially coaxially at a distance outside the shaft member. An intermediate member forming step of forming an intermediate product consisting of a rubber elastic body joined to an outer peripheral surface of the shaft member and an inner peripheral surface of the cylindrical portion and integrally connecting the outer member and at least an inner peripheral surface of the cylindrical portion; By pushing the cylindrical portion axially into the drawing hole of a drawing apparatus having a drawing hole having a diameter of a predetermined size smaller than the outer diameter of the cylindrical portion, the cylindrical portion is reduced in diameter. And a drawing step for plastic deformation.

According to this means, in the intermediate product forming step, the rubber elastic body is formed so as to be directly bonded to the outer peripheral surface of the shaft member and the inner peripheral surface of the cylindrical portion. Thereafter, in the drawing step, the entire cylindrical portion is plastically deformed by reducing the diameter of the entire cylindrical portion by axially pushing the cylindrical portion into a drawing hole of a drawing device. As a result, the rubber elastic body disposed between the cylindrical portion and the shaft member is compressed as the diameter of the cylindrical portion is reduced, and the internal pressure is applied.

Therefore, according to the manufacturing method of the vibration isolator of the present invention, the member corresponding to the conventional external metal fitting is eliminated, and the manufacture of the vibration isolator can be performed very easily, and the cost is greatly reduced. Is possible. In addition, since the press-fitting step of the external metal fittings, which has been conventionally performed, can be eliminated, a special processing step such as a polishing process and a special facility associated therewith are not required, which also makes the production extremely easy. Thus, the cost can be significantly reduced. Further, since the cylindrical portion is only subjected to the drawing process and does not involve the press-fitting process of the outer cylindrical metal fitting as in the related art, the requirement for the high dimensional accuracy of the cylindrical portion can be relaxed.

In the intermediate product forming step in the present invention, the outer peripheral surface of the rubber elastic body disposed between the cylindrical portion of the outer member and the shaft member is directly joined to the inner peripheral surface of the cylindrical portion. This is a step of forming an intermediate product having a structure. Therefore, in the joining method of the rubber elastic body and the cylindrical portion and the shaft member, when the rubber elastic body is formed by vulcanization molding, the rubber elastic body is bonded by vulcanization, or each separately formed member is bonded by an adhesive. Various methods can be adopted, or a rubber elastic body can be disposed between the cylindrical portion and the shaft member by press-fitting and joined.
When vulcanization bonding is employed as in the invention described in claim 2 described below, the number of steps can be reduced, so that an intermediate product can be easily and advantageously formed.

In the drawing step of the present invention, the cylindrical portion is axially pushed into a drawing hole of a drawing device to reduce the diameter of the cylindrical portion and plastically deform the cylindrical portion. The internal pressure is applied to the rubber elastic body disposed between the rubber elastic bodies. The drawing apparatus used here is selected from those provided with a drawing hole appropriately designed according to the shape of the cylindrical portion to be drawn and the entire outer member.

The outer member used in the present invention is made of an aluminum alloy having excellent elongation and high strength. As the outer member, a member formed by, for example, extrusion molding or vacuum die casting can be used. According to a second aspect of the present invention, in the first aspect of the invention, the intermediate product forming step includes the step of forming the shaft member and the outside so that the cylindrical portion is positioned substantially coaxially outside the shaft member. The member is disposed in a molding die, and a cylindrical rubber elastic body is formed between the shaft member and the cylindrical portion by vulcanization molding, and the rubber elastic body is formed between the outer peripheral surface of the shaft member and the cylindrical member. The method includes a step of forming a rubber molded body for forming a rubber molded body which is vulcanized and bonded to the inner peripheral surface of the shaped portion.

According to this means, when the rubber elastic body is formed by vulcanization molding, the rubber elastic body can be bonded to the shaft member and the cylindrical portion simultaneously with the formation of the rubber elastic body. And an intermediate product can be easily formed. According to a third aspect of the present invention, in the first or second aspect of the invention, the outer member includes the cylindrical portion and a bracket portion protruding from an outer periphery of the cylindrical portion. Means is employed in which the portion is provided with a hollow portion penetrating in a direction parallel to the axis of the cylindrical portion.

According to this means, when performing the drawing step,
By using the hollow portion provided in the bracket portion, a wider drawing surface of the cylindrical portion can be secured, and the drawing process can be performed more reliably and stably. In addition,
It is preferable that the hollow portion is provided at a position along the outer peripheral surface of the cylindrical portion as much as possible.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. [Embodiment 1] This embodiment is a method for manufacturing a vibration isolator constituting one end of a suspension arm mounted on an automobile. As shown in FIG. 1, this vibration isolator has a cylindrical shaft member 1 and a cylindrical member having a mounting hole 22 that is coaxially arranged outside the shaft member 1 at a distance and is axially penetrated inside. The outer member 2 made of an aluminum alloy, comprising a portion 21 and a bracket portion 23 projecting from the outer periphery of the cylindrical portion 21 and having a mounting hole 25a and a cavity 26 therein, the outer peripheral surface of the shaft member 1 and the cylindrical portion The rubber elastic body 3 has a substantially cylindrical shape, which is vulcanized and adhered to the outer peripheral surface of the elastic member 21 and is compressed by both to apply an internal pressure.

The vibration isolator is manufactured by performing an intermediate product forming step including the following preparing step and rubber molded body forming step, and a drawing step. First, in the preparatory step in the intermediate product forming step, the shaft member 1 and the outer member 2
Prepare The shaft member 1 is formed in a cylindrical shape of a predetermined size from an aluminum alloy. The outer member 2 has a cylindrical portion 21 having a mounting hole 22 penetrating in the axial direction therein, and a pair of legs 24, 24 and both legs 24 projecting from the outer periphery of the cylindrical portion 21 in substantially the same direction. And a bracket portion 23 formed of a square block-shaped connection portion 25 having a mounting hole 25a therein, which is connected to the protruding tip of the projection 24 (see FIG. 1).

A cylindrical portion 2 is provided between the pair of legs 24, 24.
A cavity 26 is formed which is formed together with the outer peripheral surface 1 and the outer peripheral surface of the connecting portion 25. The hollow portion 26 is provided in the axial direction in parallel with the mounting hole 22 and the mounting hole 25a. The outer member 2 is made of an aluminum alloy formed by extrusion. In the next rubber molded body forming step, a molding die for forming the rubber elastic body 3 by vulcanization molding is prepared, and the cylindrical portion 21 is positioned substantially coaxially outside the shaft member 1 in the molding die. Then, the shaft member 1 and the outer member 2 are arranged. In this state, a rubber molding material is injected into a cavity formed between the shaft member 1 and the cylindrical portion 21 in the molding die, and vulcanization molding is performed. The cylindrical rubber elastic body 3 is formed. Thereby, the rubber elastic body 3 is vulcanized and adhered to the outer peripheral surface of the shaft member 1 and the inner peripheral surface of the cylindrical portion 21 to form an integrated rubber molded product (intermediate product).
Is formed.

In the subsequent drawing step, the rubber molded body obtained in the preceding step is subjected to drawing using a drawing apparatus as shown in FIGS. The drawing device used here is a first drawing hole 51 into which the cylindrical portion 21 is fitted, and the bracket portion 2 formed continuously and in parallel with the first drawing hole 51.
A die 5 having a second throttle hole 55 into which the die 3 is fitted;
The press unit 6 includes a first punch 61 inserted into the first throttle hole 51 and a second punch 62 inserted into the second throttle hole 55.

The die 5 has, at a portion corresponding to the hollow portion 24 of the outer member 2, a columnar medium-sized portion 50 forming a partial wall surface of the first throttle hole 51 and a partial wall surface of the second throttle hole 55. . The first throttle hole 51 is formed to have a predetermined diameter smaller than the outer diameter of the cylindrical portion 21. On the opening side of the first throttle hole 51, an introduction hole 52 having a diameter larger than the outer diameter of the cylindrical portion 21, and provided between the introduction hole 52 and the throttle hole 51, and from the introduction hole 52 to the throttle hole 51. A tapered guide hole 53 whose diameter gradually decreases toward is formed.

The second throttle hole 55 has an outer peripheral shape corresponding to the outer peripheral shape of the bracket portion 23 of the outer member 2.
The surface of the second throttle hole 55 on the side opposite to the first throttle hole 51 (the surface corresponding to the protruding front end surface of the connecting portion 25 fitted into the second throttle hole 55) and the outer surfaces of the pair of legs 24, 24 On the corresponding surfaces, aperture surfaces 56 and 57 are formed so as to follow the dimensional change of the cylindrical portion 21 after the aperture (diameter reduction).

In order to perform drawing by this drawing apparatus, as shown in FIGS. 2 and 3, the cylindrical portion 21 of the outer member 2 is fitted into the introduction hole 52 of the first drawing hole 51 of the die 5 and The bracket portion 23 is provided at the opening of the second throttle hole 55.
Is placed in the fitted state. And the first part of the press part 6
The tip surfaces of the punch 61 and the second punch 62 are brought into contact with the upper end surfaces of the cylindrical portion 21 and the bracket portion 23 of the outer member 2, respectively, and the press portion 6 is lowered in the axial direction.

As a result, as shown in FIG.
1 is a first throttle hole 5 from the introduction hole 52 through the guide hole 53.
The rubber elastic body 3 between the cylindrical portion 21 and the shaft member 1 is compressed by being pressed into the shaft member 1 while being reduced in diameter. At the same time, the bracket portion 23 pressed by the second punch 62 and pushed into the second throttle hole 55 is restricted by the throttle surfaces 56 and 57 and undergoes a dimensional change due to the reduction (diameter reduction) of the cylindrical portion 21. The plastic deformation follows. That is, with the constriction (diameter reduction) of the tubular portion 21, the tubular portions 21 of the two legs 24, 24 are deformed in a direction approaching each other, and the connecting portion 25 is displaced in a direction approaching the tubular portion 21, The entire outer member 2 is reduced according to the amount of contraction of the cylindrical portion 21.

After the outer member 2 is drawn as described above, the intermediate product is drawn into the first drawn hole 51 of the die 5.
Then, by taking out from the second throttle hole 55 and performing post-processing, the vibration isolator as shown in FIG. 1 is completed. As described above, the manufacturing method of the vibration isolator according to the present embodiment is an intermediate product forming process in which the rubber elastic body 3 is directly bonded to the outer peripheral surface of the shaft member 1 and the inner peripheral surface of the cylindrical portion 21 in the intermediate product forming step. A product (rubber molded body) is formed, and then, in the drawing step, the cylindrical portion 21 is formed.
By axially pushing the cylindrical portion 21 into the first drawing hole 51 of the drawing device of the above, the entire cylindrical portion 21 is reduced in diameter and plastically deformed, so that the cylindrical portion 21 and the shaft member 1 are deformed. The internal pressure is applied to the rubber elastic body 3 disposed at the position.

Therefore, according to the method of manufacturing the vibration isolator of the present embodiment, the members corresponding to the conventional external metal fittings are eliminated, the manufacturing can be performed extremely easily, and the cost can be greatly reduced. Becomes In addition, since the press-fitting step of the external metal fittings, which has been conventionally performed, can be eliminated, a special processing step such as a polishing process and a special facility associated therewith are not required, which also makes the production extremely easy. Become
The cost can be significantly reduced. Furthermore, since the cylindrical portion is only subjected to the drawing process and does not involve the step of press-fitting the outer cylindrical fitting as in the conventional case, the requirement for high dimensional accuracy of the cylindrical portion can be eased.

In the intermediate product forming step of this embodiment, when the rubber elastic body 3 is formed by vulcanization molding, the rubber elastic body 3 is integrally molded with the shaft member 1 and the outer member 2 so that the rubber elastic body 3 is formed simultaneously with the formation of the rubber elastic body 3. Since the elastic body 3 is bonded to the shaft member 1 and the cylindrical portion 21, the number of steps can be reduced and the intermediate product can be easily formed. [Embodiment 2] This embodiment is a method of manufacturing a vibration isolator used as an engine mount for supporting an engine mounted on an automobile in a vibration isolating manner. As shown in FIGS. 5 and 6, this vibration isolator includes a cylindrical shaft member 7 and a mounting hole 82 that is coaxially arranged outside the shaft member 7 at a distance and axially penetrates the inside. And a bracket portion 8 projecting from the outer periphery of the cylindrical portion 81 and having a mounting hole 84 therein.
3 and the outer peripheral surface of the shaft member 7 and the outer peripheral surface of the cylindrical portion 81 are vulcanized and adhered to each other, and are compressed and applied with the internal pressure to penetrate in the axial direction. A substantially cylindrical rubber elastic body 9 having two through holes 91 and 92.

This vibration isolator is manufactured by performing an intermediate product forming step including a preparation step and a rubber molded body forming step, and a drawing step, as in the case of the first embodiment. First, in the preparation process of the intermediate product formation process, the shaft member 7 and the outer member 8 are prepared. The shaft member 7 is formed in a cylindrical shape of a predetermined size from an aluminum alloy. The outer member 8 has a cylindrical portion 81 having a mounting hole 82 penetrating in the axial direction therein, and a pair of plate-shaped brackets projecting outward from the outer periphery of the cylindrical portion 81 and having a mounting hole 84 therein. Parts 83, 83. The outer member 8 is made of an aluminum alloy formed by extrusion.

In the following rubber molded body forming step, a molding die for forming the rubber elastic body 9 by vulcanization molding is prepared, and a cylindrical portion 81 is substantially coaxially formed outside the shaft member 7 in the molding die. The shaft member 7 and the outer member 8 are arranged so as to be positioned. In this state, a rubber molding material is injected into a cavity formed between the shaft member 7 and the cylindrical portion 81 in the molding die, and vulcanization molding is performed. A cylindrical rubber elastic body 9 is formed. As a result, the rubber elastic body 9 is vulcanized and bonded to the outer peripheral surface of the shaft member 7 and the inner peripheral surface of the cylindrical portion 81 to form an integrated rubber molded product (intermediate product).

Then, in the subsequent drawing step, the rubber molded body obtained in the preceding step is subjected to drawing using the same drawing apparatus as in the first embodiment. The die of the drawing apparatus used here has a first drawing hole (in which the cylindrical portion 81 is fitted) and a second drawing hole (the bracket portion 83, formed in correspondence with the outer peripheral shape of the outer member 8). 83 is fitted). As in the case of the first embodiment, a large-diameter introduction hole and a tapered guide hole are formed on the opening side of the first throttle hole, and the cylindrical portion 81 is formed in the second throttle hole.
The stop surface is formed so as to follow the dimensional change after the stop (diameter reduction). Further, the punch provided in the press section of the drawing apparatus is configured as a single punch so as to be inserted into both the first drawing hole and the second drawing hole.

In order to perform drawing by this drawing apparatus, the cylindrical portion 81 of the outer member 8 is fitted into the introduction hole of the first drawing hole of the die, and the bracket 83 is inserted into the opening of the second drawing hole. 83 is arranged in a fitted state, the leading end face of the punch of the press section is brought into contact with the cylindrical section 81 of the outer member 8 and the upper end faces of the bracket sections 83, 83, respectively, and the press section is lowered along the axial direction. .

As a result, the cylindrical portion 81 is pushed into the first throttle hole while being reduced in diameter and is plastically deformed, and the rubber elastic body 9 between the cylindrical portion 81 and the shaft member 7 is compressed by both. The internal pressure is applied. At the same time, the bracket portions 83, 83 pushed into the second throttle holes deform while following the dimensional change of the cylindrical portion 81 due to the throttle (diameter reduction) while being restricted by the throttle surface. As a result, the entire outer member 8 is reduced in accordance with the throttle amount of the cylindrical portion 21.

After the outer member 8 has been subjected to the drawing process as described above, the intermediate product is passed through the first die hole and the second die hole.
The vibration isolator as shown in FIGS. 5 and 6 is completed by taking out from the aperture and performing post-processing. As mentioned above,
The manufacturing method of the vibration isolator according to the present embodiment includes an intermediate product (rubber molded body) in which the rubber elastic body 9 is directly adhered to the outer peripheral surface of the shaft member 7 and the inner peripheral surface of the cylindrical portion 81 in the intermediate product forming step. )
After that, in the drawing step, the cylindrical portion 81 is axially pushed into the first drawing hole of the drawing device, thereby reducing the diameter of the entire cylindrical portion 81 and plastically deforming the cylindrical portion 81. The internal pressure is applied to the rubber elastic body 9 disposed between the portion 81 and the shaft member 7.

Therefore, according to the method of manufacturing the vibration isolator of the present embodiment, the members corresponding to the conventional external metal fittings are eliminated, the manufacturing can be performed extremely easily, and the cost can be greatly reduced. In addition, the same operation and effect as those of the first embodiment can be obtained.

[Brief description of the drawings]

FIG. 1 is a plan view of a vibration isolator manufactured in Embodiment 1 of the present invention.

FIG. 2 is a plan view of a die of the drawing apparatus used in the first embodiment of the present invention.

FIG. 3 is a cross-sectional view of the drawing apparatus, showing a state cut at a portion corresponding to line III-III in FIG. 2;

FIG. 4 is a cross-sectional view of the drawing apparatus showing a state where an intermediate product is drawn by the drawing apparatus in the first embodiment of the present invention.

FIG. 5 is a plan view of a vibration isolator manufactured in Embodiment 2 of the present invention.

FIG. 6 is a front view of a vibration isolator manufactured in Embodiment 2 of the present invention.

FIG. 7 is a sectional view of a suspension bush as a conventional vibration isolator.

FIG. 8 is an explanatory view showing a state in which drawing is performed on a suspension bush as a conventional vibration isolator.

FIG. 9 is an explanatory view showing a state in which a suspension bush as a conventional vibration isolator is pressed into a mounting hole of a suspension arm.

[Explanation of symbols]

1, 7 ... shaft member 2, 8 ... outer member 3, 9 ...
Rubber elastic body 5: Die 6: Press part 21, 81: Cylindrical part 22, 82: Mounting hole 23, 83: Bracket part
Reference numeral 24: Leg portion 25: Connection portion 25a, 84: Mounting hole 26:
Cavity part 50 ... Middle part 51 ... First throttle hole 52 ... Introduction hole 53 ... Guide hole 55 ... Second throttle hole 56,5
7: throttle surface 61: first punch 62: second punch 91,
92 ... through-hole

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Naoishi Nishikawa 6,224, Kaiyamacho, Sakai City, Osaka Prefecture Inside Showa Aluminum Co., Ltd. (72) Inventor Masatoshi Enomoto 6,224, Kaiyamacho, Sakai City, Osaka Prefecture Showa Al Within Minium Co., Ltd. (72) Inventor Shoichi Sato 6, 224 Kaiyama-cho, Sakai-shi, Osaka Showa Aluminum Co., Ltd.

Claims (3)

[Claims] 1. An outer member made of an aluminum alloy having a shaft member, a cylindrical portion disposed substantially coaxially at a distance outside the shaft member, an outer peripheral surface of the shaft member, and the cylindrical portion. An intermediate product forming step of forming an intermediate product consisting of a rubber elastic body joined to the inner peripheral surface of the cylindrical portion and integrally connecting the two, and a diaphragm having a diameter of a predetermined dimension at least smaller than the outer diameter of the cylindrical portion A drawing step of axially pushing the cylindrical portion into the drawing hole of the drawing device provided with the hole, thereby reducing the diameter of the cylindrical portion and plastically deforming the drawing. Manufacturing method of vibration isolator. 2. An intermediate product forming step, comprising: disposing the shaft member and the outer member in a molding die such that the cylindrical portion is positioned substantially coaxially outside the shaft member; And a cylindrical rubber elastic body formed by vulcanization between the cylindrical part and the rubber elastic body was vulcanized and bonded to the outer peripheral surface of the shaft member and the inner peripheral surface of the cylindrical part. The method for manufacturing a vibration isolator according to claim 1, further comprising a rubber molded body forming step of forming a rubber molded body. 3. The outer member includes the cylindrical portion and a bracket projecting from an outer periphery of the cylindrical portion, and penetrates the bracket in a direction parallel to an axis of the cylindrical portion. 3. A hollow portion is provided.
The manufacturing method of the vibration isolator described in the above.